How do eggs hatch?

We had a very busy weekend around our house with 13 duck eggs and 4 chicken eggs hatching! I was sharing photos on Instagram and had a lot of questions about the hatching process and how do eggs hatch?

There are lots of sources online, but I am going to share some photos from this weekend and try to explain without using too many technical terms.

The above image shows an egg being “candled” to reveal the chicks growth inside the egg. This egg was about 7 days along in its development. The veining is really good to see! The empty spot on the left of the egg is the air sack.

Three days before my eggs are scheduled to hatch I again candle the eggs and use a pencil to draw on the egg where the air sack is at within.

Ideally, the chick will begin to “pip” or break the egg right at the edge of the air sack. If the chick is positioned correctly within the egg then its head will be close to the air cell. It is so exciting to see this first part of hatching taking place!

From here the chick will start “zipping” the egg and peck a break in the egg all the way around the air sac. From here it is able to push this end off and break out!

Below you can see the tiny little beak of a duckling as it is working on zipping its way around the egg. Notice that in the background you can see other ducklings that have already hatched. I keep the incubator closed for at least 24 hours to give the new chicks a chance to completely dry and also to keep the other eggs from losing humidity and adding difficulty to their hatching. Hatching call duck eggs and chicken eggs varies a bit, but here was our guide to hatching these call duck eggs.

One of the benefits of marking the air cell on the outside of the egg is so that I can keep an eye out for any chicks that pip in an unusual area. These are the ones that might require some assistance if they don’t progress in hatching.

How do eggs hatch? Well, they hatch with a lot of patience on our part! It is so exciting and painstaking to watch this happen, but that moment that they finally pop out of the shell is totally worth it.